Access-Control-Allow-Origin Issue using Core API via DfB Team API

I'm trying to use a Dropbox API, specifically one that allows a team administrator to take action for the team member, but I keep getting an access-control-error.

Here's my code:

$(document.body).on('click', '.viewfolders', function() {
    var teamMember = $(this).closest('tr').attr('id');
    //JSONinputs = {"list": "true"};
    jQuery.ajax( {
        url: 'https://api.dropbox.com/1/account/info',
        type: 'GET',
        dataType: 'json',
        contentType: 'application/json',
        headers: {
            'X-Dropbox-Perform-As-Team-Member': + teamMember,
            "Authorization": "Bearer " + access_token
        },
        beforeSend : function( xhr ) {
            xhr.setRequestHeader( "Access-Control-Allow-Origin", "*");                
        },
        success: function(rootresult) {               
           alert('success');
        },
        error: function(response) {
            alert('error ' + JSON.stringify(response));
        }
    });

});

Here's the error I get:

XMLHttpRequest cannot load https://api.dropbox.com/1/account/info. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' is therefore not allowed access.

Any ideas on what's going on here? Have tried using JSONP as a dataType and gotten a 401 authorization error. Not sure what I'm doing wrong here